configuring static ip on server

I just got a static ip from sbc dsl. I am using a d-link dir 655 router. First I set the router with static ip and it connected and the settings looked good, but the computers would not connect to the internet.Then I configured the router, with pppoe and set it to static ip. but the default gateway is the wrong ip # as what they gave me. Then I had a tech come and configure it and he configured it with static ip, but he set the wan to dynamic, but the gateway and broadcast were the correct ips they gave to me. but the network mask was not what they had given me. I can not get the mail to send now. First I need to know if the tech set it up correctly for the server? I am using port forwarding and the ip I used when I setup the server (192.168.1.160). He told me I can only use one static because of the kind of router I have. Thanks for the help